Indoor location based searching (LBS) mapping systems typically consist of many points of interest. Typically the points of interest are obtained from independent layers in facility drawings and have no relationship to each other. However, relationships between points of interest can be very useful for contextual search applications, which is one of the primary applications of indoor LBS. An example of such an application is a search for a printer that is near a coffee machine or to determine the location of a particular person's office. In conventional mapping systems, however, items such as printers and coffee machines, or individual's names and room numbers are stored in different layers without relationship to each other. Accordingly, improvements of LBS mapping systems are desirable.